Letter-box alarm and indicator.



NO. 882,752. PATENTBD MAR 24, 1908 I 0. F. BRIOKSON 6: R. H.BRADSHAW.

v LETTER BOX ALARM AND INDICATOR.

APPLICATION FILED SEPT.5, 1907.

IN VENTORS,

WITNESSES Nollus runs. me Limo, msn mum, a c

- IT D. sTA Es PATENT oEEIo OSCAR F. arcxson, or BERKELEY, ANDRICHARD-H; BRADSHAW, or OAKLAND,

' oALIFoRN A.

LE'r'rEaBox ALARM Ann INDICATOR.

No. 882,752 A To all whom it may concern:

Be it known that we, OsoAR F. Enronsoiv and RICHARD H. BRADSHAW,citizens of the United States, residing, respectively, at Berkeley andOakland, in the county of Alameda and State of-Califbrnia, have inventednew and useful Improvements, in Letter-Box Alarms and Indicators, ofwhich the following is a specification.

. The object of the present invention is to provide means forautomatically giving notice at a distant point that a letter or otherarticle has been deposited in a letter box or other receptacle.

The invention is capable of use in all dwellin houses, and is ofespecial value-for use in ats,-or in connection with rural deliveryboxes, which are generally placed at considerable distance from theresidences to which they belong.

. In the accompanying drawing, Figure 1 is a broken front elevation ofthe apparatus; Fig. 2 is a broken vertical section thereof; Fig. 3 isafront view of the alarm, showing the visible signal displayed when aletter has been deposited in the box; Fig. 4 is a similar view of thealarm, the rota contact maker having been removed there rom; Fig. 5is arear view of the rotary contactmaker; Fig. 6 is a front view of thesame; Fig. 7 is an edge view of the same; Fig. 8 is anenlarged brokenperspective view of the alarm.

Referring to the drawing, 1 indicates an ordinary letter box to, whichour invention is applied. Upon the inner surface of this box is securedan insulating plate 2, upon which are secured upper and lower springcontacts 3, 4, and a spring wire contact is open,

' the box,

maker 5 is secured upon said plate in the middle as shown at 6. The endsof said wire are guided by bars 7 so that when either end is movedtoward the front of the box it is adapted to be brought into contactwith the corresponding spring contact 3 or 4. Said ends are connected bycords 8, 9, the uper 8 to the hinged lid 10 of the open ing throughwhich letters are dropped into and the lower 9 --to the door 11 by whichletters are removed therefrom. It

results that, when either the lid or the door contact is made with oneor the other of said spring contacts.

12 indicates a battery, to one pole 13 of point of attachment 6 of thespring wire contact maker Specification of Letters IPatent.

Patented March 24, 1908.

Application filed September 5, 1907. Serial No. 391,44;

5, while a wire 15 16 of the battery to abindingscrew 17 o the alarm.From two other binding screws 18 and 19 lead wires 20 and 2 1 to the twospring contacts 3, 4. From the middle binding screw 17 a wire 22 leads,to electro-magnets 23 of an alarm 24,;a wire 26 then lerlding from saidmagnets to the contact post, 27

of the alarm, which is mounted on insulat' material 28, secured ontheplate 29 whic supports the alarm. The outer binding screws 18, 19 areconnected respectively by leads from the other ole A wires 38, 39, withtwo semi-circular contact 30, 31, over which can travel a rotary havingon the rear side a contact with plates, contact maker 32, spring tongue33, adapted to one or the other of said contact its edge with ratchetteeth 34 adapted to be engaged by a spring pawl 35 connected with thevibrator 36 of the electric alarm.-

The operation is as follows. Sup

mg, in which position the sprm -tongue 33 on its rear side is in contactwith t e plate 30 on I plates.- To rotate said contact maker32 it isformed on mg that the rotary contact maker 32 is in the positioncorresponding to Fig. 10f the drawthe right, and that when in thisposition the lid of the 'letter box .is raised, then thafollowingcircuit is closed. From the pole 16 of the battery by wire 15 to thebinding post 17, by wire 22 through the electro-magnets 23 by wire 26"tothe post 27, then to the vibrating arm 36, then from said arm iii twobranches, one through the plate 29 to the central forwardly projectingart 29 of said plate 29, on which is mounted t e rotary contact maker32-, and another through the spring pawl 35, thus passing throughbothbranches to said rotary contact maker 32, then by the spring tongue33 at the rear of the spring contact'maker. to the semi-circular contactright, then b 18 on the rig by wire 20 to the upper spring contact 3,then by the spring wire-5 to the central point 6, then by; wire 14 tothe other pole of the bath tery. T

withdrawn from the post 27, and'thecom tact is thereby alternatelybroken, and closed in the usual manner. At every vibration of vanced,which small fraction of a second after the opening is circuit beingclosed, the magnet is thereby energized, the vibrating arm'36 is late 30on, the a wire 38 to t e binding scrbw it, then from said binding'screwof the door, so that the contact makeri'lw mediately engages the plate30. This motion continues so loin asthe spring tongue 33 on the contactmaker engages the late 30. When the rotary contact has rotated throughhalf a rey'olution, which Mail on its front face opposite to the opening 42. in the outer case 43 of the alarm mech- 1 anisin, the springtongue 33 moves from ofl the contact plate 30 on the right and'on to thecontact plate 31 on the left. Since the door 11 of the letter box hasnot been opened, the contact of the spring tongue 33 with the plate 31.on the left does not close any circuit, and therefore, this circuit ispermanently broken until said door is opened. On the o ening of the doorthe circuit is nowagain 0 osed, and the rotary contact maker-rotates,

. so, that a blarik surface appears inthe casing,

said c'ontactmaker continuing to rotate until the spring tongue hasagain come into contact with the contact plate 30 on the right. The boxis now again in condition for giving analarm by the opening of thelidwhen a letter or other matter is deposited. 7

It is to be observed that the alarm will not r111 continuously byleaving the lid 0 en, or

by eavin the dooropen, but only so ong as both the lid and the door areopened at the same time.

The device can be attached to any form of letter box which is providedwith a movable lidcovefpig the openin forthe' letters and a door foremoving the etters. NVe claim 1. An apparatus of the characterdescribed, com rising a letter box having a lid for closing tilleopening through which the letters are deposited, and a door for removingsaid letters, an electro magnetic alarm, a battery therefor, a rotarycontact maker, a wire leac brings the \VOId 4 battery door respectively,substantially as described.

2. An apparatus of the character described,

pole of said battery to the I comprising a letter box having alid forclosing the opening through which the letters are deposited, and a doorfor removing said letters, an electro-mag'netic alarm, a batterytherefor, a rotary cont-act maker, a visible signal device carried bysaid rotary contact maker, a Wire leading-from one pole of said twosemi-circular contact plates with which said rotary contact maker canalternately contact as it rotates, means for rotating said contact makersimultaneously with the operation of said alarm, conductors leading inparallel from said plates to the other pole of the battery, havingbreaks therein, contacts for closing the respective breaks, and

means for closing the contacts by opening the lid and door respectively,substantially as described.

to the electro-magnet of said alarm,

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses. I

OSCAR F. ERICKSON. RICHARD H. BRADSHAW. Witnesses:

N. B. KEATING, FRANCIS M. WRIGHT.

